Zack's Kernel News
Zack's Kernel News
Chronicler Zack Brown reports on the latest news, views, dilemmas, and developments within the Linux kernel community.
Improving the Kernel Clock
Miroslav Lichvar recently tried to make the Linux system clock more accurate. The problem wasn't that the clock itself would drift, it was that the kernel had to round off the time values for old vsyscalls, align frequency adjustments to the clock tick, or deal with the fact that numbers couldn't be stored with arbitrary precision. All of these things would introduce small errors that would eventually build up.
The real problem was that correcting for these errors would itself take time. Miroslav instead wanted to remove some of the sources of the errors. He posted a patch to do this, which resulted in a significant improvement in his test suite.
John Stultz liked the patches, but he wanted Miroslav to add his test suite to the kernel test directory, so anyone could track the effect of future patches on clock accuracy. However, Miroslav replied that his test suite was "a mess that breaks frequently as the timekeeping and other kernel code changes."
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